BUT for Mac Mail it’s unfortunately not so simple. Open the HTML file you created within a web browser (I use Chrome), highlight the content, then hit copy, go to the signature area of your email application window and hit paste. Now, if you’re using GMail or an email client like Outlook, the next steps are simple. These steps will work no matter what means you use to create your HTML file. Personally, I do this by using HubSpot’s email signature generator. Create your HTML Email Signatureīefore you can create your Mac Mail HTML signature, you need to first generate your HTML File. Here’s a step-by-step guide to help you out. Not true, but Mac Mail hasn’t made it simple to implement. We know that HTML email signatures are great for your brand. This is something you want to have pre-built as you’re not going to want to type it out every single time you write a new email. Your social media and other contact details can also appear here. In particular, they can be a great place for a secondary CTA (call-to-action) and other necessary email footers (i.e.

Email Signatures (or email sign-offs) provide a wonderful opportunity to include your brand in an organised clean manner. You'll need to enter your PIN here, rather than clicking Sign and then getting the standard OS X dialog to enter your PIN.Adding an HTML email signature in Mac MailĪpple users might think they’re missing out on having an HTML email signature when using Mac Mail.

Once this configuration change has been made, the signature dialog box will change slightly to include a field to enter your PIN (or as Adobe calls it, 'certificate password'), as shown in the screen shot below. If you have Firefox or Thunderbird installed, then it's the same as the one you have configured in those applications in order to use your CAC. If you're using something other than CACKey, then you'll need to determine the path for your PKCS#11 module. The above steps will need to be repeated for each user account on the machine.

Click the 'Usage Options' popup menu and select 'Use for Signing'.

Click on the email signing certificate (look for one issued by DOD EMAIL CA-xx and includes Intended usage of Digital Signature).

Click the little triangles to open up the module until you see the card.

Enter path to your PKCS#11 module for CACKey this is /Library/CACKey/libcackey.dylib.

In Adobe Reader DC, open Preferences, then go to Signatures -> Identities & Trusted Certificates -> More.

sudo chmod 755 /Library/CACKey/libcackey.dylib.

sudo chown root:admin /Library/CACKey/libcackey.dylib.

If they're not, change them using Terminal.app:

Verify permissions of /Library/CACKey/libcackey.dylib are correct they should be -rwxr-xr-x (755) and owned by root, group admin.

This is the solution: it assumes you are using CACKey, but can probably be translated to other middleware:

Mac mail signature not working